I have found the cap on the bag of concentrate from my wine kits really difficult to remove. My last two kits are RJ Spagnols grand cru kits. Has anyone found an easy way to pull these caps?
I put the bag in the sink (just in case!), and hold it with one hand at the top, and give the cap a major yank without squeezing the bag. (Or you can leave the bag in the box, to avoid accidentally squeezing the bag).
I use a butter knife. Just make sure you are holding the neck of the bag very tight and that it's slightly elevated, or you'll wind up with juice all over your shorts.
Good thing I don't wear shorts while brewing. Wait, what?
Stubby handled #2 Standard screw driver blade. Never fails to cleanly pop those pesky caps. On average I do 10-12 wine kits per year, many of which have grape skin packs, so several "2-fer" kits.